The invention relates to a caulking gun comprising an elongate receiving unit for a cartridge filled with the product to be delivered, a metering unit for the product to be delivered and a handle which in operational setting extends outwardly and transversely or obliquely relative to the elongate receiving unit.
Known caulking guns of that kind are used for expelling viscous masses, for example sealing masses for joints, from cartridges. Known caulking guns consist of the receiving unit, the metering unit and a handle fixedly connected with the receiving unit. The metering unit comprises a displaceably mounted piston rod with a piston which presses against the displaceable base of an inserted cartridge so that content of the cartridge is discharged in metered manner from the opening opposite the displaceable base. A movable, usually pivotable, operating element is connected with the handle and co-operates with the piston rod. The piston rod and thus the piston are moved by manual pressure on this operating element, so that the base of the cartridge is pushed towards the metering opening of the cartridge and the content of the cartridge is pressed out of this opening, which is usually nozzle-like.
A disadvantage of the known caulking gun is the space requirement. The piston rod can indeed be pushed into the receiving unit, but the handle extending outwardly transversely or obliquely relative to the elongate receiving unit needs a relatively large amount of space. The space requirement leads to increased transport, packaging and storage costs for the manufacturer and supplier. The need for space at the point of sale is also high. Finally, the user similarly has to have a relatively large amount of space for storage of the caulking gun when not in use.
The invention therefore has the object of substantially reducing the space requirement for a caulking gun of the kind stated in the introduction when not in use.
According to the invention this object is met in the case of a caulking gun of the kind stated in the introduction in that the handle is movable from the operational setting into a rest setting in which the handle is arranged substantially parallel to the elongate receiving unit.
In the rest setting the handle therefore needs substantially less space than in the operational setting so that the caulking gun requires considerably less room for transport, packaging and storage as well as for presentation at the point of sale.
It is within the scope of the invention for the handle to be detachably connected with the remaining parts of the caulking gun. However, so that loss of individual parts of the caulking gun is avoided and user friendliness increased, it is proposed that the handle is pivotably connected with the receiving and/or metering unit. If the metering unit comprises a displaceable piston, it is additionally proposed that the handle is pivotable about a pivot axis extending transversely to the stroke direction of the piston.
To enhance operational reliability, the handle is, in a further advantageous refinement of the invention, lockable in at least the operational setting. If the receiving unit comprises a holder for reception of the metering unit it is further of advantage if the handle comprises snap connecting members co-operating with the holder so that the handle can be locked and unlocked again in simple manner.
For improvement in user friendliness it is in addition proposed that the snap connecting members comprise two hinge arms. These hinge arms are preferably disposed on the handle in the region of the pivot axis.
It is of particularly appreciable advantage if the handle is lockable in both the operational setting and the rest setting. In the rest setting of the handle the caulking gun can, in this case, also be handled particularly easily. For locking of the handle in the rest setting it is further proposed that the holder comprises snap connecting members co-operating with the free end of the handle. These can be provided in the form of, for example, a protruding tongue behind which the end of the handle can detent. In this way no additional parts on the handle are needed for the snap connection.
If in the case of use of conventional caulking guns the force exerted on the piston by the operating lever is relaxed, for example when the operating lever is released, then the substance disposed in the cartridge exerts a return pressure on the piston so that a locking mechanism is provided to prevent any rearward movement of the piston. The force thereby acting constantly on the cartridge piston is certainly of advantage during expulsion of the mass, but during interruption in work leads to an undesired escape of the viscous mass, which is termed xe2x80x9crunning onxe2x80x9d. Locking mechanisms of that kind are, in addition, constructionally complicated in conventional caulking guns and have to be separately operated, namely released, in order to prevent running on during interruption in work.
In an advantageous refinement of the invention it is therefore proposed that the metering unit comprises a braking device co-operating with the piston, so that from the constructional perspective a simple caulking gun with good metering characteristics is obtained. The braking device retains the piston rod during the expulsion process substantially in its position, when the operating lever is released, in order to begin a fresh pressing process. However, the braking device enables a slight rearward deviation of the piston rod in the case of interruption in work, so as to relieve the cartridge piston and in this way prevent running on. The known complicated locking mechanism can therefore be dispensed with, as the gun is automatically relieved when work is interrupted.
If the piston comprises a piston rod, the braking device preferably consists of a part of the holder tightly surrounding the piston rod at least partially.